Is Mimecast or office365.us more popular?

Mimecast is used by more websites in our catalog: 11,342 use Mimecast and 119 use office365.us.

Does Mimecast or office365.us have higher-authority sites?

Mimecast sites have the higher median Ahrefs Domain Rating (Mimecast: 51, office365.us: 50).

Is Mimecast or office365.us growing faster?

Between 2026-06 and 2026-07, Mimecast went from 1.6% to 1.3% of all tracked sites, while office365.us went from 0.02% to 0.01%. office365.us is gaining ground faster in our index.

Can a site use both Mimecast and office365.us?

No. A site runs a single email host, so Mimecast and office365.us are mutually exclusive.

Where does this Mimecast vs office365.us data come from?

Adoption is counted from Site Stats Database's own crawl; Domain Rating comes from Ahrefs and traffic from DataForSEO. Figures reflect the sites we track and refresh at least monthly.

Mimecast vs office365.us — Site Stats Database

Mimecast vs office365.us

A side-by-side comparison of two email hosting providers, based on the 736,999 Email Host sites tracked by Site Stats Database.

Last updated July 1, 2026

Metric	Mimecast	office365.us
Websites	11,342	119
Market share	1.5%	0.02%
Share of top 10K sites	4.2%	0.02%

Rank	#8	#144

Median DR	51	50

Average DR	48	49

Median keywords	2,113	1,113

Median referring domains	1,075	872

Median domain age	24 yrs	24 yrs

Average domain age	22 yrs	21 yrs

Average monthly traffic	372,032	134,543

Combined monthly traffic	4,219,586,311	16,010,669

clevelandclinic.org
LanguageEnglish
DR (Ahrefs)92
Total Keywords5,266,698
Referring Domains262,751
Domain Age28 yrs
Traffic (Jun 2026)536,244,433
Traffic Trend
TechnologyMimecast
cambridge.org
Language
DR (Ahrefs)92
Total Keywords4,651,462
Referring Domains357,733
Domain Age28 yrs
Traffic (Jun 2026)527,148,452
Traffic Trend
Technology
nfl.com
LanguageEnglish
DR (Ahrefs)89
Total Keywords947,630
Referring Domains147,040
Domain Age30 yrs
Traffic (Jun 2026)275,712,888
Traffic Trend
TechnologyMimecast
gettyimages.com
LanguageEnglish
DR (Ahrefs)89
Total Keywords5,589,590
Referring Domains272,498
Domain Age27 yrs
Traffic (Jun 2026)146,264,162
Traffic Trend
Technology
istockphoto.com
LanguageEnglish
DR (Ahrefs)91
Total Keywords4,131,936
Referring Domains1,685,041
Domain Age26 yrs
Traffic (Jun 2026)127,970,606
Traffic Trend
Technology
cvs.com
LanguageEnglish
DR (Ahrefs)84
Total Keywords1,535,152
Referring Domains55,537
Domain Age30 yrs
Traffic (Jun 2026)71,302,734
Traffic Trend
TechnologyMimecast
forbes.com
LanguageEnglish
DR (Ahrefs)94
Total Keywords5,061,816
Referring Domains1,192,610
Domain Age33 yrs
Traffic (Jun 2026)69,613,575
Traffic Trend
Technology
weatherbug.com
LanguageEnglish
DR (Ahrefs)77
Total Keywords780,575
Referring Domains11,435
Domain Age26 yrs
Traffic (Jun 2026)66,263,733
Traffic Trend
Technology
petmd.com
LanguageEnglish
DR (Ahrefs)85
Total Keywords827,963
Referring Domains49,308
Domain Age28 yrs
Traffic (Jun 2026)60,196,625
Traffic Trend
TechnologyMimecast
autozone.com
Language
DR (Ahrefs)78
Total Keywords1,406,463
Referring Domains30,776
Domain Age30 yrs
Traffic (Jun 2026)52,596,499
Traffic Trend
Technology

Website	Language	DR (Ahrefs)	Total Keywords	Referring Domains	Domain Age	Traffic (Jun 2026)	Traffic Trend	Technology
clevelandclinic.org	English	92	5,266,698	262,751	28 yrs	536,244,433		Mimecast

militaryonesource.mil
LanguageEnglish
DR (Ahrefs)83
Total Keywords181,601
Referring Domains20,053
Domain Age
Traffic (Jun 2026)7,947,490
Traffic Trend
Technologyoffice365.us
dni.gov
LanguageEnglish
DR (Ahrefs)83
Total Keywords19,989
Referring Domains30,302
Domain Age21 yrs
Traffic (Jun 2026)1,073,314
Traffic Trend
Technologyoffice365.us
usmc-mccs.org
LanguageEnglish
DR (Ahrefs)74
Total Keywords35,685
Referring Domains6,557
Domain Age26 yrs
Traffic (Jun 2026)938,980
Traffic Trend
Technology
magpul.com
LanguageEnglish
DR (Ahrefs)70
Total Keywords16,248
Referring Domains4,618
Domain Age27 yrs
Traffic (Jun 2026)709,984
Traffic Trend
Technology
geaerospace.com
LanguageEnglish
DR (Ahrefs)77
Total Keywords34,978
Referring Domains9,000
Domain Age14 yrs
Traffic (Jun 2026)416,103
Traffic Trend
Technology
darpa.mil
LanguageEnglish
DR (Ahrefs)83
Total Keywords10,165
Referring Domains30,909
Domain Age
Traffic (Jun 2026)370,029
Traffic Trend
Technologyoffice365.us
bellflight.com
LanguageEnglish
DR (Ahrefs)74
Total Keywords7,351
Referring Domains5,379
Domain Age8 yrs
Traffic (Jun 2026)339,471
Traffic Trend
Technology
edmundoptics.com
LanguageEnglish
DR (Ahrefs)71
Total Keywords17,802
Referring Domains7,537
Domain Age26 yrs
Traffic (Jun 2026)323,504
Traffic Trend
Technology
anduril.com
LanguageEnglish
DR (Ahrefs)75
Total Keywords16,018
Referring Domains6,887
Domain Age22 yrs
Traffic (Jun 2026)293,324
Traffic Trend
Technology
mustangsurvival.com
LanguageEnglish
DR (Ahrefs)64
Total Keywords4,593
Referring Domains1,930
Domain Age31 yrs
Traffic (Jun 2026)255,542
Traffic Trend
Technology